Sofa



FIG. 1 is a front perspective view of the design;

FIG. 2 is a back perspective view of the design; and,

FIG. 3 is a top view of the design.

The side of the sofa not seen in FIG. 2 is a mirror image of the side seen in FIG. 2. The broken lines along the seam represent stitching. 

The ornamental design for a sofa, as shown and described. 